Winding with moulded parts, method and set of moulded parts for electrical machines

ABSTRACT

The invention concerns a winding for a post or an armature of an electric machine with a post or armature ( 32 ) with slots ( 34 ) composed at least in part of L-shaped structural parts ( 1, 2, 3 ). In doing so, one leg of an L-shaped structural part each time creates a slot bar ( 8   a   , 8   b ) located in a slot, and the other leg creates a connecting line ( 6   a   , 6   b ) located at a face of the post or armature. Moreover, the invention concerns a winding with several interlaced coils ( 50, 52, 50′, 52′, 50″, 52 ″) whereby the connecting lines ( 6 ) of interlaced coils ( 50, 52, 52′, 50″, 52 ″) are staggered and therefore arranged in layers. The invention furthermore concerns a winding with connecting lines ( 6 ) flatter than the slot bars ( 8 ), styled as a fractional pitched polyphase winding with two slots per pole and branch. The invention also covers a winding consisting of several coils ( 50, 52, 50′, 52′ 50″, 52 ″), characterized by the fact that at least two coils ( 50, 52 ) are connected in series, whereby the current flows through one coil ( 50 ) in the direction of the slot head, and in the other coil ( 52 ) in the direction of the slot bottom. The invention also concerns a procedure and a set of structural parts to manufacture a winding for an electric machine.

[0001] The invention concerns windings, and in particular winding for anelectric machine with a post and/or armature with slots, as well as amanufacturing method and set of structural parts for such windings. Thewindings involved are so-called multiple layer windings.

[0002] The posts of electric machines (e.g., asynchronous or synchronousmachines in a rotary or linear design, whereby “electric machines” referboth to engines as to generators) are generally equipped with a winding.The power flowing through generates a moving magnetic field causing thearmature to move over the air gap between the post and the armature. Inmany designs, the armatures are also equipped with a winding. Thewinding is generally incorporated in the slots of a post or armature,usually running parallel or in a small angle to the rotational axis inthe case of a radial field machine.

[0003] The number of phases of the winding of a polyphase alternatingcurrent machine generally corresponds with the number of branches, whichusually cover several coils with one or more windings. Each coilgenerally lies with both its so-called “coil sides” in the slots,whereas the so-called end windings connect the sections of the windinglocated at the front of the post. The coils or serial switches ofseveral coils of a branch are generally connected on one end with apower supply. On the other end, the branches are joined, for example, atthe so-called neutral point. Alternatively, the coils could also bedelta connected.

[0004] The coils of different branches are generally placed in aninterlace pattern so coil sides of coils from other branches are to belocated between both coil sides of one coil. This is because the coilsides of different branches alternate in consecutive slots or groups ofslots in order to produce a magnetic field with a random alternateplacement. Therefore, the end windings of the interlaced coils have togo around the face of the post or armature. There are different possibleend winding arrangements known for this. In the case of a so-calleddouble or triple deck winding, the end windings of interlaced coils areplaced, for example, in different decks in lengthwise direction of theslots. In case of a basket winding, all end windings of a deck connectwith another making it look like the edge of a basket. This end windingarrangement is presented, amongst others, on page 331 of the publication“Fachkunde Eletrotechnik”, Verlag Europa-Lehrmittel,¹ Nourney, VollmerGmbH & Co., 22^(nd) edition 1999. Such end windings are fairlyprotruding and occupy nearly the entire face of the post.

[0005] End windings with wire-wound coils protrude relatively far fromthe slots because certain minimum bending radiuses need to be kept. Thismakes it more difficult to produce a compact end winding arrangementwith wire windings. Moreover, wire windings only allow for a relativelylow slot-space factor of approx. 40% since the wire generally has acircular cross-section, whereas the slots are usually straight-sidedflanked. Spooling a post or slot device with wire-wound coils is ratherexpensive and hard to automate. For this reason, early suggestions havebeen made (i.e., in DE-AS-10 06 506) to compose the winding of electricmachines of pre-engineered structural parts with a generally rectangularcross-section instead of a wire-wound formation. These pre-engineeredstructural parts are generally placed one by one in the slots of a postand electrically connected with the coils at the front. “Slot bars” arethose sections of the winding going through the slots and forming thecoil sides, “connecting lines” are those sections at the face of thepost forming the end windings.

[0006] The use of structural parts with a suitable cross-section allowsfor an increase of the space factor of the slots. The problem of theminimum bending radiuses does not exist when the structural parts at thetransition between the slot bar and the connecting line arepre-engineered angle-bent, allowing in principle for compact end windingarrangements. The known state-of-the-art structural part windings withinterlaced coils generally require a lot of different and often complexstructural parts in order to make the interlaced coils of the endwindings evade.

[0007] DE 197 36 645 A1 suggests for example to assemble the winding foran electric machine with C-shaped structural parts. The winding of acoil is composed of two C-shaped structural parts placed in thecorresponding slots in such a way that the open sides face one another,and by connecting the legs of the structural parts at one face. The legsforming the connecting bars are shaped flatter than the sections of thestructural parts in the slots (slots bars) in order to make the endwinding arrangement as compact as possible. The end windings ofinterlaced coils evade because the connecting lines are out of line withthe direction of the depth of the slot bars, bundling the connectinglines of a coil at a certain height of the slot depth. A connecting partrunning in the direction of the slot depth between the slot bar and theconnecting line creates this offset bend of conduit. Extra space isneeded for the connecting parts mounted at the face creating the offsetbend. The publication furthermore suggests to make the c-shapedstructural parts of sheet metal stampings folded in such a way thatthere are enough sheet metal layers in the area of the slot bar toachieve the desired ratio between the slot bar thickness and theconnecting line thickness.

[0008] DE 44 11 749 C2 describes a post winding composed of U-shapedstructural parts welded together in the slot area instead of at theface. First, the entire winding is made without a post, which is addedafterwards around the finished winding by placing individual segmentsmade of soft magnetic materials inside the winding. For this winding,the connecting lines are also made flatter than the slot bars in orderto enable the different branches to evade at the face. Since thethreephase wave winding with one slot per pole and branch shown hereonly allows for a parallel guiding of a maximum of two branches, theevasion is only possible by placing the connecting lines alternately inan upper or lower layer of connecting lines in the direction of the slotdepth. A spiral coil cannot be used for this construction since thestructural parts shown do not allow for switching from one windingposition to another. “Winding position” refers to all slot bars of awinding with the same distance to the bottom of the slot.

[0009] DE 43 21 236 C1 shows a winding made off S-shaped structuralparts, each composed of one slot bar and two connecting line halves,bend towards different sides. The connecting lines have the samethickness as the slot bars and run in an angle in the width- andlengthwise direction of the slot. This arrangement allows for allconnecting line halves of a winding arrangement to be placed at the samedistance to the bottom of the slot. In case of numerous interlacingbranches, the connecting line halves of the structural parts thereforeprotrude relatively far from the slots. The structural parts are placedinto the slots of a post viewed from the head of the slot, and thenconnected with the superimposed ends of connecting line halves belongingto different winding arrangements. This creates a wave winding withseveral branches, whereby the winding arrangement of each branchswitches every time it passes through the end winding.

[0010] DE 196 32 390 A1 further develops this winding with relativelyinexpensive structural parts by offsetting each connecting line halve byone half of the thickness of the slot bar in the direction of the slotdepth, and by connecting them at the end of the slot bar. Even though abranch is still offset by the thickness of one slot bar when runningthrough the connection between two connecting line halves, the offset ofthe connecting line to the slot bars compensates this. This arrangementalso shows a wave winding. The structural parts are very complex andtherefore expensive to manufacture.

[0011] The invention describes different aspects of windings for anelectric machine with a post and/or armature with slots:

[0012] According to a first aspect (claim 1), the winding containsseveral interlaced coils with at least one complete winding presented atthe faces of the connecting lines located at the post or armature. Theconnecting lines of interlaced coils are staggered and thus arranged indifferent layers.

[0013] According to a second aspect (claim 2), the winding is composedat least in part of L-shaped structural parts. One leg of such anL-shaped structural part presents a slot bar arranged in a slot, and theother leg presents a connecting line located at one face side of thepost or armature.

[0014] According to a third aspect (claim 3), the winding includesseveral coils composed of connecting lines arranged in the slot bars inthe slots with connecting lines at the face sides of the post orarmature. The connecting line is flatter than the slot bars. The windingis designed as a multiphase fractional pitch winding with two slots perpole and per branch.

[0015] According to a fourth aspect (claim 4), the winding includesseveral coils composed of slot bars in the slots and connecting lines atthe front of the post or armature. In each case, at least two coils arelaid out in a serial switch, whereby the power runs through one of thecoils in the direction of the head of the slot heads and the other coilin the direction of the bottom of the slot.

[0016] According to another aspect, the invention targets a productionmethod for such a winding. The following steps are repeated severaltimes: (a) The installation of structural parts in the slots of the postor armature until a complete winding arrangement or part of a windingarrangement is used, and (b) the connection of the structural partsinstalled in step (a) with conductor rails or structural parts used in aprevious passage.

[0017] According to yet another aspect, the invention is aimed at a setof structural parts for the manufacturing of a winding for an electricmachine. This set of structural parts includes one type of an L-shapedstructural part or two types of L-shaped structural parts withconnecting line legs flatter than the legs of the slot bar. The set ofstructural parts preferably includes two types of L-shaped structuralparts, from which one type is designed to create a connection in one andthe same winding arrangement, whereas the other one is designed tocreate a transition from one winding arrangement into the next.

[0018] Finally, the invention is also aimed at a winding for an electricmachine, whereby the winding consists of only one or two types ofstructural parts. Moreover, the winding possibly has one or two moretypes of structural parts for the purpose of creating a circuit for thewinding.

[0019] The invention is clarified below with preferred design examplesand the attached sample drawing. The drawing shows:

[0020]FIG. 1a An exploded view of a first type of L-shaped structuralpart;

[0021]FIG. 1b Sections along lines A-A and B-B in FIG. 1;

[0022]FIG. 2 An exploded view of a second type of L-shaped structuralpart;

[0023]FIG. 3 An exploded view of another type of L-shaped structuralpart;

[0024]FIG. 4 An exploded view of yet another U-shaped structural part;

[0025] FIGS 5 a-c An exploded view of L-shaped structural partsassembled in different ways;

[0026]FIG. 6 An exploded view of an arrangement of several L-shapedstructural parts;

[0027]FIG. 7 The same view as in FIG. 6 but with an additional L-shapedstructural part;

[0028]FIG. 8 The same view as in FIG. 7 but with an additional L-shapedstructural part;

[0029]FIG. 9 An exploded view of a post or armature section of anelectric machine with slots in which L-shaped structural parts have beenplaced;

[0030] FIGS 10 a-c Diagrammatic top views of the slots of the post orarmature at different points in time during the production of thewinding;

[0031]FIG. 11 A diagrammatic top view of the slots of a post or armaturewith U-shaped structural parts;

[0032]FIG. 12 A diagrammatic view of the face of a spooled post;

[0033]FIG. 13 A winding diagrammatic view of a threephase winding inaccordance with a design sample;

[0034]FIG. 14 An exploded view of a first design of a conductor railset;

[0035]FIG. 15 An exploded view of the conductor rail for the neutralpoint from FIG. 15;

[0036]FIG. 16 An exploded view of another design of the conductor railset according to the invention;

[0037]FIG. 17 A diagrammatic cross section of a joint of a conductorrail;

[0038]FIG. 18a An exploded view of another design of a conductor railset;

[0039]FIG. 18b A diagrammatic top view of a conductor rail;

[0040]FIG. 19 An exploded view of a section of a post completelyequipped with a winding and a conductor rail set.

[0041] Those parts in the drawings with the same or similar functionsare in part marked with the same reference signs.

[0042] The following clarification of the preferred designs using postwindings has been added for the purpose of simplification; thisstatement equally applies to the corresponding armature windings. FIGS9-11, for example, show equal views of a post (in the case of FIG. 9, itis an interior armature device) as well as an armature (in the case ofFIG. 9, it is an exterior armature device).

[0043]FIG. 1 shows a first type of structural parts. Before clarifyingthis figure, here are some remarks concerning the preferred designs.

[0044] The preferred designs apply to windings for the post of a radialfield device with an interior armature. Therefore the lengthwisedirection of the slot has been designed as the axial direction, and thedirection of the depth of the slot as the radial direction. However, thewindings described can also be used for exterior armature and lineardevices; furthermore, they can be used as armature windings. An axialfield device can also be equipped with an appropriate winding providedthe connecting lines have been adapted to the different cylinder jacketshapes of the faces.

[0045] The post shown in the figures consists of a post body in the formof a stack of slotted sheet metal in order to incorporate the slot barsof the winding for guiding the magnetic flow. The unslotted part createsthe so-called backside. The “faces” refer to the sides of the post bodywhere the slots are cut crosswise. In the case of the radial fielddevices shown, these are the axial foreparts of the post body.

[0046] The term “conductor rails” refers to the current conductorconnecting the winding with the power supply. The multiphase windingsdescribed generally use a number of phases equal to the number ofconductor rails used for the power supply and—in case of a starconnection—a conductor rail for the neutral point, the connecting pointof the phase branches of the winding. The conductor rails do not applywhen the branches are delta connected. Several conductor rails areplaced next to one another to create a conductor rail set.

[0047] The aspects of the described designs clarified individually beloware usually presented in the drawings in combination with one another,even though each aspect can also be realized individually in a winding.

[0048] One aspect of the designs described consists of composing thewinding at least in part with L-shaped structural parts (L-structuralparts), whereby one leg of the L-structural part creates a slot bar andthe other leg a connecting line basically running in the direction ofthe pitch and vertically to the first leg. Connecting the bare end ofthe slot bar of one structural part with the bare end of the connectingline of another structural part creates a connected winding, and usingthe preferred designs creates a winding composed of spiral coils. Inthis case, two L-structural parts connected with one another form onewinding of a coil.

[0049] The diameter of the slot bars is determined by the diameter ofthe slot, e.g., rectangular slots will have a rectangular diameterwhereby the width basically corresponds with the width of the slot.Consequently, several slot bars are placed on top of one another in oneslot. The diameter of the connecting lines, for instance, may also berectangular. They are, however, favorably flatter than the slot bars,enabling the connecting lines of the coils to be interlaced next to oneanother in radial layers, for example.

[0050] The connection between the bare end of a slot bar (slot bar end)and the bare end of a connecting line preferably consists of a flattenedjoint bar placed in the connecting area of the slot bar end at theconnecting line end and weld them together. The connecting area haspreferably been flattened to the extent that the combined thickness ofthe joint bar and the connecting line does not exceed that of theconnecting lines in the other areas.

[0051] In other designs (not shown here), the slot bars and theconnecting lines of different structural parts are not connected withjoint bars, but with a differently shaped extension of the slot barattached to the corresponding place or in a corresponding recess at theconnecting line. The structural parts are, for example, welded orsoldered at the joints, or connected mechanically with clamping jointsor sockets and then welded or soldered, if need be.

[0052] According to another aspect of the described design, the entirewinding requires only few structural parts. One design only requires twodifferent types of L-structural parts, apart from a possible circuitconnection for the coils, whereby the connecting line legs must beflatter than the slot bar legs. A first design has been styled to createa connection in one and the same winding location, whereas anotherdesign has been styled to create a transition from one winding locationinto the next. A preferred design has a flattened joint bar at the endof each slot bar leg, whereby the flattened joint bar and the flatterleg of one type of an L-shaped structural part are both located at thelevel of the top of the slot bar leg. In case of the other type ofL-shaped structural part, the flattened joint bar is located at thelevel of the bottom of the slot bar leg. In this case, a type 1structural part represents one half of a coil winding. A type 2structural part completes the winding, whereby the connecting line ofthis structural part takes the winding to the next winding arrangement.Alternating structural parts of type 1 and type 2 creates a spiral-likecoil.

[0053] Another design requires only one structural part to build thewinding. In this case, coils could be assembled of L-structural parts oftype 2 only, for example, provided the slots are large enough to allow asufficient air flow in the direction of the depth of the slot for theconnecting lines between the structural parts. Another option is toplace every other slot in a radial position to the other slots in orderto allow for a winding with L-structural parts of a certain type.

[0054] If need be, other types of structural parts may be used to createa circuit for this type of winding. If necessary, an additionalstructural part connecting two coils connected in series could beprovided, for example. This structural part is preferably L-shaped andcomposed of two slot bar legs and one connecting line section, and isflatter than the slot bar leg. If need be, another structural part isused to connect a coil with a power supply. In certain designs, this isanother type of L-shaped structural part with connecting line legsflatter than those of the slot bar and an extended flattened joint barat the end of the slot bar leg in order to create a connection with aconductor rail. In other designs, these joint bars are located at theconductor rails allowing the use of a standard type 1 or 2 structuralpart to connect the winding.

[0055] In the preferred manufacturing method, L-structural parts areplaced in the slots of the post on axial of the faces. This offers theadvantage that the slots can be narrowed at the head with pole shoes,thus making the effective air gap smaller. Once the structural partshave been put in place, they are all connected at the individual slotbar ends with the connecting line leg of the face of the opposingstructural part.

[0056] In the described method, the structural parts are placed inlayers and connected with one another. For this, the winding arrangementis put in place first and the other winding arrangements follow radiallyfrom the outside to the inside. The flattened joint bars of the slotbars are placed from above, i.e., radially from the inside onto thecorresponding connecting places enabling to reach the connecting areasfor welding (e.g., with a laser beam). Of course, the winding can alsobe mounted in the reverse direction, i.e., from the inside to theoutside. In this case, the connecting places are welded radially fromthe outside.

[0057] In the detail, step a shows how one slot bar leg of an L-shapedstructural part is placed in several slots, e.g., every other slot, atthe face of the post. The slot bars of the structural parts can possiblyend up in the same winding position. In step (b), the structural parts'(see step a) slot bar ends which have not been covered yet by otherstructural parts, are connected at the opposing second face with theconnecting line legs of the previously installed structural parts orconductor rails. The slots remaining from step (a) are now all filled atthe second face (step c) with a slot bar leg of an L-structural part),covering the joints created in step b. In step (d), the slot bar ends ofthe structural parts installed in step (c) are connected at the firstface with the connecting bar legs of the underlying structural parts.These steps are repeated until the slots are filled completely or almostcompletely all the way up to the slot head with slot bars. If necessary,structural parts with geometric characteristics suitable for creating acircuit in the winding are installed next. U-shaped structural parts areused through which two spiral-shaped coils are connected in series, orone connecting piece connecting the winding to a conductor rail, forexample.

[0058] According to another aspect of the preferred design, theconnecting lines of interlaced coils are twisted in each other with atleast one entire winding. In this case, the connecting lines are placedin layers and preferably flatter than the slot bars, e.g., so flat thatthe connecting lines of the different interlaced coils belonging to onewinding arrangement do not exceed the thickness of one slot bar. Byplacing several such layers of twisted connecting lines on top of oneanother, the coils can be composed of any number of windings. Theconnecting lines of the winding according to DE 197 36 645 A1 are alsoflatter than the slot bars. In this case however, the connecting linesof interlaced coils are not placed in a staggered way at the faces, butbunched together with the end winding. In order to be able to reach theindividual bunches, each connecting line is placed (crimped) offsetacross from the slot bar connected in the direction of the slot depth.This presents disadvantages (several different structural parts, spacerequired for the placement). In case of a twisted placement of theconnecting lines, it is no longer necessary to offset the connectingline across from the slot bars, thus decreasing the space needed for theend windings.

[0059] In order to let the flattened connecting lines of interlacedcoils in a twisted arrangement run by without crimping, the faces of thepost are placed, for example, at a slant angle with the connecting linebetween both slots from which the slot bars connect them. The connectingline refers to the vertical line on the median of the section of thepost defined by both slots. Consequently, the connecting line runs in adifferent direction for each pair of slots. The slant commutation layersthe connecting lines of a winding in a scaled pattern on top of oneanother.

[0060] The examples describe a winding composed of staggered connectionlines in L-shaped structural parts. In other designs (not shows here),such a winding is, for example, composed of separate slot bars andconnecting lines (I-structural parts), C- or U-shaped structural parts,or composed of structural parts covering a complete winding at the timeof the placement (O-structural parts).

[0061] In order to make the winding at the faces as compact as possible,a winding pattern with the fewest possible end windings in an interlacedpattern next to one another was found to be favorable. A simple exampleof this would be a rotary winding with one slot per pole and branch(one-slot winding): In this design, each of the faces has only two endwindings in an interlaced pattern. This is different in case of windingswith several slots per pole and branch (multi-slot windings), forexample, which are used to create a more favorable field in comparisonwith one-slot windings and are better adjusted to an alternate design.The winding pattern for a rotary current two-slot winding shown on page331 of “Fachkunde Elektrotechnik”, for example, shows each fourinterlaced end windings at each of the faces. Even a compact staggeringof the connecting lines would result in a further protrusion of the endwindings. This is because the connecting lines used would generally haveto be made wider in order to make up for their low thickness (factor 4)in order to have approximately the same cross-sectional area of the lineas the slot bars.

[0062] The described designs have a fractional pitch winding enabling areduction of the number of end windings running by one another inmulti-slot windings. The coil width of a fractional pitch winding issmaller than the pole pitch. “Pole pitch” refers to the distanceexpressed in the slots between two magnetic poles. The slot widthindicates how many slots have to be between the first and the secondcoil side. The preferred designs have a pole pitch 6, but a coil widthof only 5. This means that the end windings of the coils are shorterthan those in a non-fractional pitch winding since they only have tobridge four instead of five slots. Consequently, the winding sections atthe faces are shorter and therefore take up less space thus reducing theresistance loss. In the case of the rotary two-slot winding shown, thepitch of the winding allows to run only three instead of four endwindings in an interlaced pattern, for example. This type of fractionalpitch winding pattern is extremely favorable for structural partwindings in the sense that it allows for a compact end winding area. Itcan, however, be used for windings made of wire formation offeringcorresponding advantages.

[0063] The windings shown in the design examples have severalspiral-like coils whereby two coils are switched in series in such a waythat the current in one coil runs through the spiral in the direction ofthe slot head, and the other in the direction of the bottom of the slot.The connecting lines of the coils are flatter than the slot bars, arelayered on top of one another at a slant angle in respect to theconnecting line between both slots, and connected with the slot bars. Aspiral-shaped coil is formed, for example, when the connecting linesfrom one face connect slot bars of the same arrangement, and theconnecting lines on the other face connect slot bars from radialsuperimposed layers. This type of winding can be made of L-structuralparts, for example. In principle, other structural parts (e.g., U-, C-,I- or O-shaped) or wire-wound coils can also be used.

[0064] The serial switch of two spiral-like coils shown allows theconnections to the conductor rails to be arranged either at the bottomor at the top of the slot, in other words, both on the same side of theconnecting line. This is especially favorable when the conductor railstack is also placed on this side of the connecting line. In case ofsingle coils (not connected in series), on the other side, a connectingpiece would have to be placed crosswise over the connecting line fromthe slot end to the slot bottom, which would require space in the axialdirection. A serial switch allows for a connecting piece switching bothcoils in series to run parallel to the connecting lines, thus layeredradially in a compact way over the connecting lines. The connectingpiece could be the centerpiece of a U-shaped structural part, forexample.

[0065] The structural parts used in the design examples—whether they areL-shaped or differently—are made with non-cutting or cutting metalforming or working techniques such as founding, extruding, sintering,stamping, pressing, milling and bending, or a combination of thesemanufacturing techniques. The structural parts could be milled, forexample, of a piece of sheet metal of the same thickness as the slotbars, the thickness of the milling parts near the connecting lines andthe flattened joint bars would be reduced by closed-die stamping, andfinally the material displaced as a result of the stamping would be cutoff.

[0066] Alternatively, a structural part could alternatively be made ofsemi-finished products, joined with resistance welding, for example. Apreferred design would use an L-shaped structural part composed of twobar-shaped so-called I-structural parts with a different cross-sectionform. In this case for example, one I-structural part would form the legof the connecting line and another I-structural part would form the legof the slot bar. The leg of the slot bar could be made of a piece ofsquare wire, whereas a flat wire or a connecting line could be made of apunched flat piece, for example. Because of the simple shape of theI-structural parts, they can be manufactured with little waste.

[0067] In another design, the structural parts are composed of severallayers. In this case, a bar-shaped component is placed on a flat,L-shaped structural part in the area of the slot bar, for example,making the area of the slot bar thicker. Several layers could be placedon top of one another. In another design, a similar result can beachieved by folding a flat base material in such a way that the desiredthickness is obtained in the area of the slot bar.

[0068] The structural parts contain conductive materials such as copperor aluminum, or alloys of these metals, and have been mutuallyinsulated.

[0069] The windings described are preferably connected with revolvingconductor rails along which several coils or groups of coils placed inparallel. These are connected at regular distances determined by thewinding pattern along the perimeter of the conductor rail. Therefore,the coil ends are not connected with connecting pieces to centralconnection points, but could be connected (e.g., welded) directly withthe conductor rails.

[0070] The winding designs shown stand out by its compact end windingarea. In particular, the connecting lines are shaped so flat andarranged in such a way that the end windings do not take up more radialspace at the faces than the depth of the slot allows. Therefore, thefront-end surface of the post below the slot remains uncovered. Thesurface is, in other words, the surface at the back of the post, whichserves to feed back the magnetic current. This area is available tocreate a circuit for coils. By placing the conductor rails or othercomponents creating a circuit for the winding in this area, the spacecan be filled up completely on at least one face of the post, thusminimizing the axial expansion of the magnetic non-active space of thepost. Moreover, the conductor rails are located close to the coils.Therefore, the conductor rails for the connection of the winding arepreferably installed in the direction of the slot depth below theconnection line.

[0071] In a first design, several or all conductor rails are layerednext to one another in the lengthwise direction of the slots, i.e., inan axial direction, for example, preferably making them border directlyto the end windings and therefore allowing for a direct connection withthe winding at a short distance. At least one conductor rail at the sidefacing the connecting lines should have a raised side where the coilends can be connected. According to another design, on the other hand,several or all conductor rails are layered on top of one another in thedirection of the depth of the slot. In both cases, at least oneconductor rail on the side facing the connecting lines is equipped withjoint bars stretching out over the other conductor rails and eachconnected with one coil end.

[0072] In a fair number of designs, the connecting pieces create anotherconductor rail between two and two coils in serial switch each time,composed of several sectors insulated against one another with fourcoils each connected in series.

[0073] Incidentally, the configuration with revolving conductor rails isgenerally favorable for any type of winding for an electric device withcoils placed in parallel. The description on hand thus also reveals awinding structure for an electric device with a polyphase winding andseveral coils or sets of coils of the winding placed in parallel andconnected with a revolving conductor rail. In this case, the othercharacteristics described in claims one through four are not present(but could be optionally present).

[0074] The designs described generally use the space at the faces of apost in a compact way, allowing in particular for little axial expansionof the non-active magnetic volume of the post. Moreover, the preferredstructural part winding has a high space factor, allowing for a hightorque density. Therefore, the preferred designs are very appropriatefor the crankshaft starter generator of a motor vehicle, i.e., anelectric device serving as a starter and a generator. This device sitsin a concentric position on the crankshaft of an internal combustionengine and is preferably connected with this shaft without interstageyet with torsional strength. The starter-generator has a limitedexpansion capability because of the limited housing space, on the otherhand, the direct start requires a high torque.

[0075] Returning to FIGS. 1-4, these figures individually present andclarify the structural part types used for the preferred winding.

[0076] Figure one shows an exploded view of an L-structural part 1 ofthe first type. A leg 8 a of the L-structural part 1 creates a slot bar8 in the finished winding, whereas the other leg 6 a is located at thefaces of the post and connects slot bars 8 lying in different slots.Therefore, slot bars and connecting lines are generally marked withreference numbers 8 and 6, respectively, whereas the slot bar legs andconnecting line legs of certain structural parts are indicated withreference numbers 8 a, 8 b and 6 a, 6 b respectively.

[0077] The connecting lines 6 are flatter and wider than the slot bars8, as shown in the cross-sections of both legs 6 a and 8 a in FIG. 1b.The slot bars 8 actually have a thickness H and a width B, whereby thewidth B in the designs shown has been selected to allow for severalslots bars in one slot next to one another, i.e., at the same heightfrom the slot bottom. Thickness h of the connecting line 6, for example,is one third of thickness H of the slot bar 8, whereas width b is aboutthree times width B of the slot bar 8. This means that the cross-sectionof the line in both legs of the structural part shown is about the same.

[0078] Structural part 1 has a flattened joint bar 10 a at the bare endof the slot bar 8 a. The joint bar 10 a of the first type shown infigure one lies at the same height as the connecting line 6 a, i.e., onthe bottom side of the slot bar leg 8 a in the drawing. This means thatthe (invisible) bottom side of slot bar 8 a of the connecting line 6 aand a slot bar 8 a lying close to the transition region 12 of the jointbar 10 a are on the same level. The transition region 12 of the jointbar 10 a shows about the same thickness as the connecting line 6 a,i.e., approx. one third of the thickness of the slot bar. At the far endof the joint bar 10 a, there is a connecting region 13, which isflattened even more compared with the transition region 12, i.e., toabout one sixth of the thickness of the slot bar. The transition betweenregions 12 and 13 is made with a step at the lower side of the joint bar10 a. The connecting region 13 thus leaves a free space of approx. onesixth of the thickness of the slot bar at the bottom side compared withthe height of the bottom side of the slot bar 8 a.

[0079] Two structural parts are connected by placing the connecting area13 of the joint bar 10 aat the end of the connecting line of a secondstructural part. The connecting area 13 is then connected, e.g., welded,with the connecting line of the second structural part. Therefore, theconnecting region 13 of joint bar 10 a does not have an insulating coat,just like the joint 16 at the end of the connecting line 6. This ismarked in the drawing with a shaded line. Structural part 1 and allother structural parts shown which are not marked with a shaded linehave an insulating coat. In order to make sure that the connecting layerlocated in the densely packed end winding area between two structuralparts is not thicker than a connecting line 6, the joint 16 of theconnecting line 6 a has been flattened to about half the thickness ofthe connecting line 6 a. This way, the joint bar connecting region 13can be placed and welded to a joint 16 without exceeding the thicknessof the connecting line 6 at the connecting region. Since the thicknessof the transition region 12, which has been kept as short as possible,and the actual connection is only about one third of the slot bar 8 a,it comes with a cross-section contraction. This is accepted in favor ofa densely packed end winding arrangement of the connecting line. Thetransition region 12 can be favorable since it creates a distancebetween the slot bars and the end winding. The cross-section of the lineshould be as big as possible. The transition region 12 could also bedesigned as a continuous transition between the slot bar and theconnecting region 13. In other designs where the transition region 12has been left out, the connecting region 13 is directly connected withthe slot bar 8.

[0080]FIG. 2 shows a second type of an L-shaped structural part 2, usedto create a complete winding of a spiral coil in combination with thefirst type. Structural part 2 basically has the same design asstructural part 1, i.e., the lengths and the cross-sections B-B and A-Aof the connecting lines 6 a, 6 b and joint bars 8 a, 8 b of bothstructural parts are the same. Structural part 2 also has a flattenedjoint bar 10 b at the bare end of the slot bar 8 b. Contrary to the slotbar 10 a of structural part 1, the flattened joint bar 10 b is notlocated at the same height as the connecting line 6 b, but offset withthe opposing area of the slot bar 8 a. The joint bar 10 b of structuralpart 2 is actually located at the height of the side (located on top inFIG. 2) of slot bar 8 b, whereas the connecting line 6 b—just like withstructural part 1—is located at the same height as the bottom side ofthe joint bar 8 b. For the rest, the joint bar 10 b of structural part 2is laid out the same way as joint bar 10 a of structural part 1: Itshows a transition region 12 directly following the slot bar 8 b andabout as flat as the connecting line 6 b, and yet another flattenedconnecting region 13 at the outer end of the joint bar 11. This region13 is so flat that its thickness together with the thickness of theflattened joint 16 of a connecting line 6 is about the same as thethickness H of a connecting line 6. The step between transition regions12 and 13 is located at the downwards pointing side of the entire jointbar 10 b in such as way that the top side of the entire joint bar 10 bis located at the same height as the top side of joint bar 8 b.

[0081]FIG. 3 shows a third type of L-shaped structural part 3, used toconnect the winding with the conductor rails. Structural part 3 isbasically the same as structural part 1, but comes with an extendedjoint bar 26 instead of the joint bar 10 a. This extended joint bar 26is connected, e.g., welded, with a conductor rail and therefore has noinsulation. The thickness of slot bar 26 is preferably the same as thethickness h of a connecting line 6. Structural parts 3 are favorablylocated in the lower winding arrangement of the slots, bordering theextended joint bars 26 directly to the conductor rails placed below theslot bars, if need be. Another option would be to place the structuralparts 3 in the top winding arrangement.

[0082] In another preferred design, the joint bars are placed on theconductor rails in order to connect the winding with the conductorrails. In this case, no special structural parts 3 of the third type areneeded and the joint bars 10 a of the structural parts 1 of the firsttype, for example, are welded on the extended joint bars 26 of theconductor rails.

[0083] Finally, FIG. 4 shows a type of U-shaped structural part used tocreate a serial switch for two spiral-shaped coils of one winding. TheU-shaped structural part 4 has two slot bar legs 8 b, 8 b′. The lengthand the cross-section A-A of these slot bar legs are the same as thoseof the slot bar legs 8 a, 8 b of structural parts 1 and 2. Both slotbars 8 b, 8 b′ have a flattened joint bar 10b at the bare end. Thisjoint bar 10 b is located in the drawing at the topside of the slot bar8 b, 8 b′, respectively, and therefore corresponds with the slot bar 10b of the L-structural part 2. The connecting line 7 connecting both slotbars 8 b, 8 b′ has the same cross-section B-B as the connection lines 6a, 6 b of structural parts 1 and 2. They are, however, one slot lengthlonger. If the connecting lines 6 a, 6 b of the structural parts of thefirst and the second type are, for example, long enough to create a coilwith slot bars 8 within a distance of five slots, the connecting line 7of the U-structural part is extended by connecting two coils, here forexample in such a way that both slot bar legs 8 b, 8 b′ end up at adistance of six slots from one another. Another typical detail of theconnecting line 7 is that it is not located at one and the same levelrelative to both slot bar legs 8 b, 8 b′. It is rather located at theheight of the top side (in the drawing) of a slot bar leg 8 b on oneside, yet on the other side at the height of the bottom side of theother slot bar leg 8 b′. If both slot bar legs 8 b, 8 b′ of aU-structural part in a finished winding are in the same windingarrangement, the U-structural part consequently lies at a slight slantangle with both slot bars 8 b, 8 b′ to the connecting line between bothslots. The ends of the connecting line legs of these L-shaped structuralparts are flattened, as indicated with a welding 27. The U-shapedstructural part could be made of two L-shaped structural parts, forexample, with flattened areas at the end of the connecting line legs.These flattened areas are placed on top of one another and weldedtogether.

[0084]FIG. 5 shows different possibilities to create an L-structuralpart from different parts instead of only one entire part. The preferreddesign shown in FIG. 5a has an L-structural part made, for example, oftwo bar-shaped I-structural parts. The lengths and cross-sections of theI-structural parts required for the connecting line 6 and slot bar 8 aredifferent and could be made of semi-finished products, for example. Aslot bar 8 could for example be made by cutting off a square wire withan appropriate cross-sectional shape. A joint bar 10 is stamped on oneend (not shown) of the square wire, and the displaced material is cutoff. The other end is stamped and cut off in a similar way to create arecess 22 which is placed in an extension 21 and can be connected withthe slot bar. The connecting line 6 is preferably stamped from a flatstrip. If need be, a flattened joint 16 is stamped at a corner of theconnecting line 6 and the recessed material is cut off. The slot bar 8and connecting line 6 are preferably resistance welded together. Forthis, welding knobs are preferably stamped in the extension 21. The endof the slot bar 8 shown is possibly stamped even more so this slot barend has the same thickness as the extension 21 of the connecting line 6.The symmetry created this way between the thickness and the sink heatproves to be favorable. Proper methods to create an electric connectionbetween the connecting line 6 and the slot bar 8 shown in FIG. 5a are,amongst others, welding (with a laser beam), soldering or gluing with aconductive glue, as well as positive or non-positive connections.

[0085] The L-structural part in the variants shown in FIG. 5b and cconsists of multiple layers. The structural part in FIG. 5b, forexample, consists of a flat L-shaped layer 18 and a second layer 19applied only in the area of the slot bar. The parts of layer 18protruding from underneath layer 19 create the connecting line 6 on oneside and the joint bar 10 a on the other side. This means that thestructural part is a type 1 part. Another layer 20 is added as shown inFIG. 5c in order to create a type 2 structural part where the joint bar10 b and the connecting line 6 are not located at the same level isadded as shown in FIG. 5c. This layer protrudes from the slot bar endover layer 19, thus creating a joint bar 10 b. The thickness of layer19′ in FIG. 5c is thinner than layer 19 of FIG. 5b by one time thethickness of layer 20. The layers placed on top of one another arepreferably soldered, welded (ultrasonic, laser beam or resistancewelding), tox clinched or stamp packed.

[0086] Next, the construction of a winding with overlapping coils madewith L-structural parts will be described as per FIGS. 6 through 8.These figures show the composition of the bottom winding layer with fewstructural parts. For the sake of simplicity, the structural parts arepresented without a post lying down on a flat surface. In case of a postbody of a radial field device, the structural parts would be located onthe interior sheath surface of a cylinder. FIG. 6 shows three type 3L-shaped structural parts with extended joint bars. The structural parts3 are located in the winding arrangement right at the bottom of theslots and placed in an offset pattern two slot lengths apart, so eachsecond slot of slot bar 8 a contains one structural part 3. The extendedjoint bars 26 are all located at the same face of the post body andconnected with the conductor rails (not shown) underneath. Theconnecting lines 6 on the other side of the post body are placed on topof one another in a scaled pattern, thus creating a layer 28 ofconnecting lines. Inside the layer of connecting lines 28, theconnecting lines are layered in such a way that the bare end is alwayslocated in the upper part of this layer and the joint 16 is exposed andaccessible, whereas other connecting lines 6 a cover the other end. Thetransition between the connecting lines 6 a and the slot bar 8 a of thesame L-structural part 3 is covered by other connecting lines 6 a. Thetransition between the connecting lines 6 a and the slot bar 8 a of thesame L-structural part 3 is located in the covered area.

[0087] As the drawing shows, the connecting layer 28 contains threeconnecting lines 6 a on top of one another. Since the thickness h of theconnecting lines 6 a in the design shown is about one third of thethickness H of the slot bar 8 a, the connecting line layer 28 is nowherehigher than the corresponding layer of slot bars 8 a.

[0088] In the example shown, the connecting lines 6 a connect slot barsevery five slots, as clarified below. In other designs (not shown), theconnecting lines connect slot bars at a bigger or smaller distance sothere are also more or less three connecting lines on top of one anotherin one connecting line layer. The thickness h of the connecting lines 6is favorably selected in such a way that the thickness of eachconnecting line layer 28 corresponds with the thickness H of a slot bar8. Other designs, which do not specify a certain structural connectingpart for the conductor rails, use structural piece of the first type inthe first assembly steps following FIG. 6.

[0089] Once each slot has a structural part 3 in accordance with FIG. 6,each remaining slot is each filled with one structural part of type 2 insuch a way that its connecting line 6 b ends up on top of the connectinglines 6 a of the structural parts 3 inserted previously and located onthe opposing face of the post (see FIG. 7). The connecting region 13 ofthe flattened joint bar 10 b of structural part 2 herewith ends up onthe flattened joint 16 of the connecting line 6 a of structural part 3.The structural part 2 is connected with structural part 3 in thislocation, i.e., by welding with a laser beam. A laser beam with adequateenergy is pointed at the exposed surface 14 of the connecting region 13of the joint bar 10 b. This melts the material of the connecting region13 of the joint bar 10 b, merging it with the underlying joint 16 of theconnecting line 6. Alternatively, there is a groove in area 13 of thejoint bar 10 b, enabling to point the laser beam directly through thisgroove at the edge between the end of the joint bar 13 and the joint 16underneath. In this case, the laser beam does not have to melt theentire thickness of the end of the joint bar 13.

[0090] Since the end 13 of the joint bar 10 b of structural part 2—asclarified in FIG. 2—is located at the level of the top of the slot bar 8b, the slot bar 8 b of structural part 2 ends up in the same windingarrangement as the slot bars 8 a of the structural parts 3 when it isplaced on top of the connecting region of the connecting line 6 a. Thiseliminates the difference in height created by the scaled pattern at aslant angle of the connecting lines 6 a in the connecting line layer 28.

[0091] At the opposite face, the connecting line 6 b of structural part2 is also located at a slant angle, i.e., at the covered end at the sameheight as the extended joint bars 26 of the structural parts 3. Fromthis point to the bare end, it is only covered over this joint bar.

[0092]FIG. 8 shows the same winding arrangement as FIG. 7, with anadditional structural part 2′ corresponding with structural part 2.Structural part 2′ is connected the same way as structural part 2, i.e.,with the end of its joint bar end area 13 at the end of its slot bar leg8 b′ with the joint 16 of structural part 3. It is connected on theopposite side with the connecting line 6 b′ in a layered scale-likepattern over the connecting line 6 b of structural part 2 in such a waythat the joint 16 ends up over the slot bar end of structural part 3connecting the joint bar end area 13 of structural part 2′.

[0093] A complete winding arrangement of slot bars 8 is obtained byadding additional structural parts 2 and 3 in each second slot inaccordance with FIG. 8. The connecting lines of structural parts 2 and2′, respectively, then form a second connecting line layer 30 similar tolayer 28 on the other face. Each bare end of connecting lines 6 a, 6 bof the structural parts 2, 3 faces upwards in these layers in such a waythat the joints 16 are not covered by connecting lines of the samelayer. The connecting line layers 28 and 30 are each layered at a slantangle in such a way that the connecting line 6 b (in the exploded viewof the drawing) runs from the left bottom to the right top, and theconnecting lines 6 a from the right bottom to the left top.

[0094] A complete winding of a spiral shaped coil is built by weldingstructural part 2 to the matching structural part 3. The connecting line6 b of structural part 2 layered at a slant angle takes the winding tothe next-higher winding layer. The spiral is extended by putting astructural part 1—not shown in FIG. 8—on structural part 3 of the firstwinding. This creates the start of the new winding layer. The connectingarea 13 of joint bar 10 a thus puts structural part 1 on the joint 16 ofthe corresponding structural part 2 and is connected with it asdescribed above. Since the slot bar 10 a of structural part 1 is locatedat the level of the bottom of the slot bar 8 a of structural part 1, theheight difference created in the connecting line layer 30 resulting fromthe slant layering is not leveled out. On the contrary, it ends upcreating a spiral. Structural parts of type 1 are placed on allstructural parts 3 in order to create a complete winding. These type 1structural parts are again welded at the corresponding joints 16 of thestructural parts 2. Additional structural parts 2 are placed in theremaining slots, i.e., each second slot on top of the structural parts2, and then welded to the joints 16 of structural parts 1, thuscompleting this second winding arrangement. The connecting lines ofstructural part 1 create another connecting line layer 28. Thecomposition of this layer is the same as the connecting line layer 28 ofstructural parts 3 shown in FIG. 8. Once the second winding layer hasbeen installed and connected, several interlaced coils with each twowindings with connecting lines staggered in one another have beencreated.

[0095]FIG. 12 shows a diagrammatic presentation of the staggering of theconnecting lines of interlaced coils. This figure shows a diagrammatictop view of the faces of a spooled post. The front surface of theconnecting lines 6 b is marked in a simplified way with lines. Theconnecting lines 6 b are arranged in four slant layers 30 on top of oneanother. The connecting lines 6 b of the different branches are markedwith different lines, e.g., the connecting lines of branch V withcontinuous lines, the connecting lines 6 b of branch W with dash-dottedlines and the connecting lines of branch U with a dashed line. Thedifferent branches alternate within one connecting line layer 30.Layering multiple similar layers and the corresponding connectionsbetween the structural parts of these layers creates spiral shaped coils50, 52, 50′, 52′, 50″, 52″ with staggered connecting lines. Eachconnecting line 6 b of a layer 30 belongs to another coil. Theconnecting lines of branch V, for example, belong to coils 50, 52, thoseof branch W to coils 50′, 52′, and the connecting lines of branch U tocoils 50″, 52″. Coil 52″ overlaps coils 52, 52′ on one side and coils50, 50′ on the other side.

[0096] On the other face, the connecting lines 6 a are arrangedcorrespondingly, with the difference that the connecting lines 6 a ofthe layer 28 each connect slot bars from winding layers lying uponanother, which results in them passing into the next-higher windinglayer after each winding.

[0097] The end winding arrangement shown in FIG. 12 can also be used forwinding which are not composed of L-structural parts, but of any otherrandom structural parts. In principle, the end windings of wire-woundcoils can also be staggered instead of evading in bunches at the faces.Even though FIG. 12 shows a three-phase two-slot winding, any randomwinding of an alternating or direct current generator can be created ina way that the connecting lines of interlaced coils are staggered.

[0098] Just like FIG. 6 through 8, FIG. 9 shows a part of the windinglayer located under the slots. The drawing no longer shows theidealization of a leveled developed view, but a cutout of a bent post 32of a radial field device in an interior armature design (or an armaturein an exterior armature design) with structural parts 2, 3 placed in theslots 34. In order to make the actual winding better visible, the designonly shows the two faces of the post body 32. The post body 32 is solidof course, and typically composed of electric sheets layered uponanother in an axial direction. This means that each face presented ofthe post body 32 corresponds with the outer sheets of the armaturestampings.

[0099] Structural parts 2, 3 are located directly above the bottom ofthe slot in the slots 34. The head 36 of the slots 34 is narrowed so theL-structural parts 2 and 3 can only be slipped in the slots in an axialdirection. The face from the spectator's point of view has already beenput in a layer of structural parts 3 and three structural parts of type2 have been put on the opposite face.

[0100] The bent presentation of FIG. 9 reveals that the connecting lines6 of the L-structural parts are slightly bent in a radial direction.This is meant to layer the connecting lines in the most compactconnecting line layer 28 on one side, and on the other side to followthe perimeter of the post body. The flexion shown of the connecting linecan follow when the structural parts are installed. It is also possibleto build the structural parts with the required curvature or to bendthem as needed before the installation. FIG. 9 also shows that the slotsin the post body of the radial field device shown converge in a radialdirection from the slot bottom to the slot head. This means that thedistance between two slots is smaller at the slot head than at the slotbottom. It is easy to level this difference in a winding composed ofL-structural parts shown since the exact distance between two slot bars8 a, 8 b connected with one connecting line 6 a or 6 b is not defined.The connection area 13 of the joint bars of a slot bar 8 a or 8 b canrather be placed at a random spot on the connecting line 16 with theconnecting line 6 a or 6 b of a second structural part and where it willbe connected with it. The width of the connecting area 16 should haveadequate tolerance.

[0101] Next, a manufacturing example of the method used to create awinding is clarified on the basis of FIGS. 10a-c. Each figure shows adiagrammatic top view of the slotted side of a post or an armature—oneshould picture the post or armature body cut open again and wound off inone tier. The narrowing of the slots at the slot head is not shown here,allowing a full view of the top winding layer in the slots. The slotsare all numbered from 1 through 12 since the winding arrangement used inthis example is repeated every 12 slots.

[0102]FIG. 10a shows the post after finishing the first step of themanufacturing process with a structural part 3 placed in the directionof the arrow P in each second slot 1, 3, 5, 7, etc. of the post facelocated in the top section of the drawing. All connecting lines 6 of thestructural parts (in the drawing) point to the left. The structuralparts 3 are placed in the slots in sequence from the left to the rightto allow for all bare ends of the connecting line 6 to be radiallyaccessible once all structural parts 3 of this layer have been placed.The structural parts 3 in the slots 1, 5 and 9 all show an extendedflattened joint bar 26 at the bare end of the slot bar. This joint baris suitable for connecting the winding with a conductor rail (not shownhere) for the current supply phases. The structural parts in the slots3, 7 and 11 also show a flattened slot bar 26′, which is shorter in thisexample than the extended slot bars 26, and lie on a conductor rail 40for the star point.

[0103] Once the structural parts of this first (partial) layer of thewinding have been installed, a second step consists of welding theflattened slot bars 26′ and 26 with a laser beam to the subjacentconductor rails.

[0104] Next, a structural part 2 is placed in the direction of the arrowQ in each remaining slot from the opposite face (located at the bottomin the drawing) as shown in FIG. 10c. These structural parts are placedin a way that the connecting line 6 b of the structural parts 2 in thedrawing point to the right. The flattened joint bars 10 b at the bareend of the slot bars 8 b of structural part 2 all end up on the bare endof a connecting line 6 of a structural part 3. Once all structural parts2 of this winding arrangement have been placed, the flattened joint bars10 b are welded with a laser beam to the subjacent bare end of thestructural parts 6. The winding design presented here has grooves 11 inthe flattened slot bars 10 b, through which the welding laser beam isable to point directly at the connecting line 6 of a structural part 3.

[0105]FIG. 10c shows the post at the end of the next manufacturing step.Here, structural parts 1 are pushed in every other slot 1, 3, 5, 7, etc.in the direction of the arrow P, viewed from the upper face of the postin the drawing. This is done in such as way that the structural parts 1end up directly opposite the structural parts 3 placed in step 1. Theflattened joint bars 10 a of the structural parts 1 are each at the bareend of a connecting line 6 of a structural part 2 installed in step 3.Once all structural parts 1 have been placed, the flattened joint bars10 a of the structural parts 1 are welded with a laser beam to thesubjacent connecting lines 6 of the structural parts.

[0106] The steps shown in FIGS. 10b and 10 c are repeated until allslots are filled with slot bars, except for the top winding layer.Opposed to the step shown in FIG. 10b, in which structural parts of type2 are placed from the bottom face, U-shaped structural parts of type 4are placed as shown in FIG. 11. In the drawing, not all U-structuralparts have been pushed in completely. The U-structural parts 4 markedwith a shaded line each have two slot bars 8 b and 8 b′ placed in theslots 2 and 8, 4 and 10, 6 and 12. This means that there is a slot barleg of a U-structural part in every other slot. The connecting line 7 ofthe U-structural parts are also layered on top of one another in ascaled pattern on the lower face of the post, just like the connectinglines 6 of the L-structural parts. The connecting lines 7, however, areall one slot distance longer than the connecting lines 6 of theL-structural parts. Consequently, the flattened joint bars 10 b of theslot bars 8 b, 8 b′ of the U-structural parts all end up on the bareends of coils belonging to different connecting lines 6 a of structuralparts 1 and are welded with a laser beam in this last step.

[0107] Two spiral shaped coils are connected in series in eachU-structural part. The following is a detailed description of this inreference to FIG. 12. As mentioned above, FIG. 12 is a highlydiagrammatic top view presentation of one face of a spooled post. Theface in question corresponds with the lower face shown in FIGS. 10 and11. FIG. 12 shows the back of the connecting lines 6 b placed on top ofanother in several layers 30. For the purpose of pictorialization, thecurrent direction in one of the branches has been marked with arrows inthe drawing. The branch U marked with a continuous line starts at pointA with a connection to a conductor rail. From there, the branch isguided into a spiral shaped coil 50 over four winding layers or fourconnecting line layers 30, respectively, to the slot head. The dottedline represents a connecting line 6 on the opposite face of thearmature. This connecting line 6 connects a U-structural part. Theconnecting line 7 of this U-structural part runs over the face shown.Two coils 50 and 52 with an equal layout are connected in series throughthe U-structural part in such a way that the current flows in anopposite direction through both coils, following the directions of thearrows. This means that the current in the spiral shaped coil 52depicted flows from the slot head to the slot bottom, whereas in coil50, it flows from the slot bottom to the slot head. The branch isconnected at the star point at point B. The other branches, depictedwith dashed or dash-dotted lines, respectively, mark connections withthe conductor rails as well as corresponding U-structural parts withconnecting lines 7, which have not been marked in FIG. 12.

[0108]FIG. 13 shows the winding arrangement for the winding shown inFIGS. 1 through 12. It shows how the individual coils are distributedover the slots of the post, whereby this winding arrangement has onlyone coil side in each slot (single-layer winding). The windingarrangement is repeated every 12 slots and laid out as a threephasewinding (rotary winding) with two slots per pole and branch (two-slotwinding). This results in a pole pitch of six, i.e., the distancebetween two poles is six slots. In case of a full-pitch winding, thecoil width, i.e., the distance between both coil sides of a coilexpressed in slots full-pitch winding, therefore also equals six. Thecoil width of the winding shown in FIG. 13, however, is smaller than thepole pitch, i.e., equals five. Therefore this is a so-called fractionalpitch winding. The fractional pitch results in the winding heads of nomore than three coils are guided along one another at the faces of thepost. For the winding designs described above, this means that a compactwinding head arrangement is obtained when the thickness h of theconnecting line is one-third or smaller than the thickness H of the slotbars.

[0109] A branch V in FIG. 13 is printed in bold for the purpose ofclearness. The other branches U, W run accordingly. Branch V consists oftwo coils 50, 52 connected in series, which are presented here in asimplified way as closed rings—whereas they actually are spirals witheight windings, for example. On one side, the coil 50 is connectedelectrically with the conductor rail 44 for branch V, and on the otherside with the coil 52 via a connecting piece 7 (which could be aU-structural part, for example) bridging six slots. This is (in a designnot shown in FIG. 13) connected with the conductor rail marked with a Yfor the star point 40. The immediate current direction has been markedwith arrows. Both coils 50, 52 are located in neighboring slots withtheir coil sides facing one another, in such a way that the current inboth neighboring slots flows in the same direction. There are each timefour coil sides of coils from other branches between the coil sides of acoil 50, 52.

[0110] The arrangement of the winding heads does not become clear fromthe winding arrangement of FIG. 13. If, however, the connecting linesare layered in a compact way as described above, there is hardly anyspacing in the densely packed “winding head arrangement. Therefore, theconnecting pieces 7 necessary to connect two coils in series are eitherconveniently located at the slot head or at the slot bottom, i.e., atthe edge of the winding head package. If the winding basically consistsof spiral shaped coils (i.e., coils in which the connecting lines do notoverlap in a radial direction), a connecting piece 7 connects two coils50, 52 in series at once in such a way that the current flows in thedirection of the slot head in one coil and in the other coil in thedirection of the slot bottom. However, since the above describedlayering of the connecting line is identical for both coils 50, 52,connecting piece 7 connects both coils 50 and 52 in series in such a waythat the current flows in an opposite direction, i.e., negative phasesequence, through both spirals. As a result of this serial connection,the connections between the branches and the conductor rails for thecurrent supply 42, 44, 46, as well as for the star point 40automatically all end up on one radial side of the winding head package,actually on the other side of the connecting pieces. The conductor railsare also conveniently located on this side.

[0111] An alternative consists of connecting four coils, or another evennumber of coils in series each time, as shown of FIG. 13. The windingarrangement of FIG. 13 has two pairs of coils connected in series areagain connected in series each time with another connecting piece 48.The connecting pieces 48 can be laid out the same way as the connectingpieces 7; following another layout, they create sectors of an additionalconductor rail.

[0112] FIGS. 14-19 show compact design examples of the conductor railpackage. The conductor rails run around the post allowing the connectionof several coils or groups of coils placed in parallel along theperimeter. The current flow through the current supply of conductorrails is generally higher. Therefore, the diameter of the conductorrails is relatively large in order to minimize the resistance losses. Asa result of this, the conductor rails take up a lot of space. In orderto limit the axial expansion of the post as much as possible, theconductor rails in this area in the examples shown are arranged in aradial way next to the slot openings on one face of the post. Thesurface at the face remains bare anyway in the compact winding headarrangement described above, and this space-saver can therefore be usedfor the current supply. The conductor rail packages are thereforeparticularly suited for connecting the winding described above. However,they can be combined with any winding, in principle.

[0113]FIG. 14 shows an example of an arrangement of the conductor railsfor a rotary current winding according to a first design. As mentioned,the conductor rails are arranged in the direction of the slot depthbelow the winding heads and connected with connection 49 with the rotarycurrent source in this case. The conductor rails shows in FIG. 14 arelayered on top of one another in lengthwise direction, i.e., axialdirection of the slots, in such a way that each conductor rail ends updirectly adjacent to the radial inside of the winding heads. The joints60, 62 connecting the branches with the conductor rails are thereforearranged on the radial inside of the conductor rails. The winding cantherefore be directly connected, for example welded or soldered, to theconductor rails 40, 42, 44, 46 without any other connecting pieces, forexample when the winding consists in part of special structural parts 3with extended joint bars 26 at the slot bar end reaching all the way tothe joints 60, 62.

[0114] It should be guaranteed, however, that each extended joint bar 26contacts only one of the conductor rails 40, 42, 44 or 46. For thispurpose, the joint 62 of the conductor rails 42, 44, 46 are equippedwith an electric insulating coat with windows, offsetting one another insuch a way that each joint bar 26 contacts one window at the most.According to another variant shown in FIGS. 14, 15 and 17, the currentrings at the contact points 62 show elevations, so-called welding bulges63, sticking out radially to the inside. If an extended joint barcontacts a welding bulge 63 and is welded to it, the joint bar is keptat a distance of the other conductor rails at the same time. The weldingbulge 63 is stamped for example into the conductor rails 42, 44, 46 bypressing the conductor rails 42, 44, 46 in an axial direction at thosespots where a welding bulge 63 should be created, thus creating a bulge63 from displaced material on the radially inwards facing side of theconductor rail. The displaced material could be shaped like a protrudingbanner, for example (see FIG. 17).

[0115] If need be, the winding is not only connected for the currentsupply with the conductor rails, but also with a conductor railconnecting three branches, the so-called star point. Alternatively, thebranches can also be delta connected, thus eliminating the need forconductor rails for the star point. Since the current in the threephases of a rotary current source are dephased by 120° to one another,the sum of the currents flowing in the star point nearly equals zero atany time. For the sake of saving space, the conductor rail for the starpoint 40 has therefore a smaller cross-sectional area than the conductorrails 42, 44, 46 for the current supply, i.e., the cross-sectional areais thinner in an axial direction than the other conductor rails 42, 44,46. The star point conductor rail 40 in the example shown in FIG. 14 istoo thin to have a structural part of the winding welded on the innerradial area of a structural part of the winding. Therefore, it has jointbars 60 instead of welding bulges 63 extending in an axial directionover the radial inner area of the other conductor rails. The extendedjoint bar 26 of a structural part 3 could be welded on these joint bars60, for example. For the sake of clearness, FIG. 15 presents theconductor rail for the star point 40 with the joint bars 60 without theother conductor rails.

[0116] The conductor rail packet shown in FIG. 14 is suitable forconnecting a threephase winding with any winding layout. The conductorrail packet shown in FIG. 16, on the contrary, is very suitable forconnecting the rotary current winding with four coils each connected inseries. It has the same components as FIG. 14, in particular threeaxially layered conductor rails 42, 44, 46 connecting the winding withthe electric current supply. These conductor rails all have joints 62shaped as welding bulges 63, as well as a conductor rail 40 for the starpoint, which is equipped with joint bars 60 extending over the radialinterior surface of at least one of the conductor rails. It additionallyhas another rail, a sector piece conductor rail 48 arranged on theradial inner side of the conductor rail package, whereby the joints 60and 62 of the remaining conductor rails 40, 42, 44, 46 are accessiblethrough the corresponding recesses in the sector conductor rails 48 andcan be put in contact with the winding. The sector piece conductor rail48 is not continuous, but consists of sector pieces insulatedelectrically from one another. They build the connecting pieces markedas 48 in the winding arrangement of FIG. 13 between two pairs of coilsconnected in series. For this purpose, the extended joint bars 26 ofstructural parts 3 of the coils 52 and 54 belonging to the differentcoil pairs are welded with both ends of a sector 48.

[0117] Following yet another design, the conductor rails are layered ina radial direction as shown in FIG. 18a, and not in an axial direction.Only one conductor rail 46 is arranged directly at the winding heads inthis arrangement, whereas the other conductor rails 42, 44 do not havedirect access to the winding. Therefore, all conductor rails areequipped with joint bars 61 protruding radially to the inside over otherconductor rails or over the winding heads if need be. The winding isconnected for example by bending the end of these joint bars 61 to theinside, and welding the extended joint bar 26 of a structural part 3 tothe bent end. This example also allows for arranging a conductor rail 48subdivided in sectors in a radial direction on the inside of theconductor rail packet, or arranging a conductor rail for the star pointin a radial or an axial direction over the other conductor rails 42, 44,46. The conductor rails could be made of rings cut out of a plate, forexample. This results in quite a bit of waste however. Therefore, it ispreferred to create the conductor rails by bending a bar with anappropriate cross-section or individual ring sectors. FIG. 18b showssuch a conductor rail 40, 42, 44, 46 made off individual ring sectors.Press fitting is preferred to connect the sectors, whereby extensions47, for example, are pressed in corresponding recesses in the ends ofthe sectors. The conductor rails are favorably turned into a packet insuch a way that the joints between the sectors of interlaced conductorrails are offset, thus increasing the stability of the conductor railpacket.

[0118]FIG. 19 shows a winding design in a post of an electric radialfield machine with a conductor rail packet, corresponding with the oneshown in FIG. 18. The space-saving use of the area at the face of thepost 32 becomes very clear here, as well as the staggered arrangement ofthe coils overlapping the connecting lines 6.

[0119] The windings described in the different examples of arrangementscan be made with a few different, simple structural parts and stand outbecause of a space-saving arrangement of the winding heads.

1. Method to manufacture a winding made of structural parts for a postand/or armature of an electric machine with slots (34), whereby thefinished winding encompasses several interlaced coils (50, 52, 50′, 52′,50″, 52″) with at least one complete winding, showing connecting linesat the faces of the post or the armature, characterized by a staggeredarrangement of the connecting lines (6) of interlaced coils (50, 52,52′, 50″, 52″) and thus forming layers (28, 30), characterized by theuse of L-shaped structural parts, a layered composition of the winding.Therefore the composition requires to repeat the following steps a andb: (a) use of L-shaped structural parts (1, 2, 3) in the slots of thepost or armature until an entire or partial winding arrangement has beenplaced, and (b) connect the structural parts placed in step (a) withconductor rails (42, 22, 46) or with structural parts (1, 2, 3) placedin a previous stage.
 2. Winding following claim 1 characterized byarranging the L-shaped structural parts (1, 2, 3) on the faces of theslots (34) of the post or armature (32) and connected each time to awinding by connecting, in particular welding, the bare end of the slotbar leg (8) of a first structural part (1) with the connecting line leg(6) of a structural part (2) placed from the opposite face.
 3. Procedurefollowing claim 1 or 2, characterized by a repetition of the stepsmentioned in claim 1 until at least some slots are filled up until onewinding arrangement; the slots are then filled with structural parts (4)suitable to create a circuit for the coils (50, 52).
 4. Winding for anelectric machine with a post and/or armature with slots (34), wherebythe winding encompasses several interlaced coils (50, 52, 50′, 50″, 52″)with at least one complete winding composed of structural parts (1, 2,3) each time, whereby the coils (50, 52, 50′, 50″, 52″) presents slotbars (8) and connecting lines (6) located at the faces of the post orthe armature, whereby the connecting lines (6) of the interlaced coils(50, 52, 52′, 50″, 52″) are staggered and therefore layered (28, 30) andcharacterized by the fact that the winding is made by a layeredplacement of L-shaped structural parts (1, 2, 3) in the slots (34) andwelding structural part joints (13, 16) covered by the L-shapedstructural parts (1, 2, 3) of the next layer (28, 30) of structuralparts (1, 2, 3).
 5. Winding for an electric machine with a post and/orarmature (32) with slots (34) following claim 4, characterized by thefact that a leg of an L-shaped structural part creates a slot bar (8 a,8 b) located in a leg, and the other leg creates a connecting line (6 a,6 b) on one face of the post or armature.
 6. Winding for an electricmachine with a post and/or armature with slots (34) following claims 4or 5, characterized by the fact that the winding encompasses severalcoils made of slot bars (8) located in the slots and connecting lines(6) located at the faces of the post or armature, whereby the connectinglines (6) are flatter than the slots bars (8), whereby the winding islaid out as a fractional pitch winding with two slots (34) per pole andbranch.
 7. Winding for an electric machine with a post and/or armaturewith slots (34) following one of the claims 4 through 6, characterizedby the fact that the winding encompasses several coils (50, 52, 50′,52′, 50″, 52″), composed of slot bars (8) located in the slots andconnecting lines (6) located at the faces of the post or armature,whereby at least two coils (50, 52) are connected in series, whereby thecurrent flows through one of the coils (50) in the direction of the slothead and the other coil (52) in the direction of the slot bottom. 8.Winding following claim 7, characterized by the fact that two coils (50,52) are each time connected in series by a U-shaped connecting piece (4)created with two slot bar legs (8 b, 8 b′) and a connecting line section(7).
 9. Winding following claim 7 or 8, characterized by the fact thatthe current flows in an opposite direction through two coils connectedin series (50, 52).
 10. Winding following one of claims 7 through 9,characterized by the fact that the onsets (26) of the coils are allarranged on the same side—viewed in the direction of the slot depth) ofthe connecting line (6).
 11. Winding following one of claims 4 through10, characterized by the fact that the connecting line (6) is flatterand wider than the slot bars (8).
 12. Winding following one of claims 4through 11, characterized by the fact that the connecting lines (6) ofinterlaced coils (50, 52, 50′, 52′, 50″, 52″) are styled flatter thanthe slot bars (8) in such a way that the layer (28, 39) of connectinglines (6) belonging to one layer of slot bars (8) is not higher than aslot bar (8).
 13. Winding following one of the above claims,characterized by the fact that the connecting lines (6) at the faces ofthe post or armature each time run at a slant angle with the connectingline of both slots (34) from which the slot bars (8) are connectedthrough the individual connecting lines (6).
 14. Winding following oneof claims 4 through 13, characterized by the fact that one coil (50, 52,50′, 52′, 50″, 52″) is created by connecting slot bars (8 a, 8 b) of thesame layer with connecting lines (6 a) located on one face, and theconnecting lines (6 b) located on the other face connect the slots bars(8 a, 8 b) of overlapped layers—in the direction of the sloth depth. 15.Winding following one of claims 4 through 14, characterized by the factthat the structural parts are composed of several layers.
 16. Windingfollowing one of claims 4 through 15, characterized by the fact that theL-shaped structural parts (1, 2, 3) are made of two bar-shapedI-structural parts with a different cross-sectional shape and/orcross-sectional area.
 17. Winding following one of the claims 4 through16, characterized by the fact that the bare end slot bars (8 a, 8 b) ofthe L-shaped structural parts have a flattened joint bar (10 a, 10 b).18. Winding following claim 17, characterized by the fact that the bareends of the connecting lines (6 a, 6 b) of the L-shaped structural partshave a joint (16) on which the flattened joint bar (10 a, 10 b) of thesecond structural part can be placed to create a connection with asecond structural part.
 19. Winding following one of the claims 4through 18, characterized by the lack of an offset in the direction ofthe depth of the slot (8) between a slot bar (8) and the attachedconnecting line (6).
 20. Winding following one of claims 6 through 19,characterized by the fact that the winding is styled as a threephasetwo-slot winding with a coil width of five slots.
 21. Winding followingone of claims 4 through 20, characterized by the fact that several coilsor groups of coils placed in parallel are connected with a revolvingconductor rail.